The preparation of macromolecular monomers, such as polystyrenes having polymerizable end groups, has been described in the prior art. One such prior art is U.S. Pat. No. 3,786,116. This same patent teaches the copolymerization of such macromolecular monomers with other monomers capable of polymerizing therewith to form thermoplastic graft copolymers such as the ones useful in the present invention. The oil resistance of certain such graft copolymers is known from this same patent.
The block copolymer rubbers useful in this invention are also well-known compositions, as described below, and their lack of resistance to oil is also well-known.